Gramineous Plants Research Articles

CYP6FD5, an antenna-specific P450 gene, is potentially involved in the host plant recognition in Locusta migratoria

Cytochrome P450 monooxygenases (P450s) are a large superfamily of heme-thiolate proteins and play a vital role in the biosynthesis and inactivation of endogenous substances as well as the detoxification of exogenous substances. They also function as odor-degrading enzymes (ODEs) in insect olfactory sensory systems. In the present study, a P450 gene was obtained from the antennae of Locusta migratoria and named as CYP6FD5. Multiple alignment of P450 proteins revealed that LmCYP6FD5 contained five conserved motifs, including the helix C motif, an oxygen-binding site, helix K motif, a meander region, and the haem-binding motif. The expression of LmCYP6FD5 in various tissues and antennal development stages was determined by using RT-qPCR. Our results showed that LmCYP6FD5 was antenna-specific and highly expressed throughout the antennal developmental stages of female and male locusts. Furthermore, the role of LmCYP6FD5 in the perception of host plant volatiles was assessed using RNAi in combination with electroantennogram (EAG) and behavioral responses. Our findings showed that after silencing LmCYP6FD5, the EAG responses of female and male locusts to the main volatiles of gramineous plants, including trans-2-Hexen-1-al, cis-3-Hexenyl acetate, and decanal, were significantly diminished. Moreover, a significant decrease in EAG response of male antennae to benzaldehyde was also observed. In addition, behavioral assay showed that the locust response to single volatile from host plant or wheat remained unchanged after the silencing of LmCYP6FD5. Antenna-specific expression and EAG responses of locusts to host plant volatiles still suggested that LmCYP6FD5 was potentially involved in host plant recognition, although no behavioral changes were observed.

The CC-NB-LRR protein BSR1 from Brachypodium confers resistance to Barley stripe mosaic virus in gramineous plants by recognising TGB1 movement protein.

Although some nucleotide binding, leucine-rich repeat immune receptor (NLR) proteins conferring resistance to specific viruses have been identified in dicot plants, NLR proteins involved in viral resistance have not been described in monocots. We have used map-based cloning to isolate the CC-NB-LRR (CNL) Barley stripe mosaic virus (BSMV) resistance gene barley stripe resistance 1 (BSR1) from Brachypodium distachyon Bd3-1 inbred line. Stable BSR1 transgenic Brachypodium line Bd21-3, barley (Golden Promise) and wheat (Kenong 199) plants developed resistance against BSMV ND18 strain. Allelic variation analyses indicated that BSR1 is present in several Brachypodium accessions collected from countries in the Middle East. Protein domain swaps revealed that the intact LRR domain and the C-terminus of BSR1 are required for resistance. BSR1 interacts with the BSMV ND18 TGB1 protein in planta and shows temperature-sensitive antiviral resistance. The R390 and T392 residues of TGB1ND (ND18 strain) and the G196 and K197 residues within the BSR1 P-loop motif are key amino acids required for immune activation. BSR1 is the first cloned virus resistance gene encoding a typical CNL protein in monocots, highlighting the utility of the Brachypodium model for isolation and analysis of agronomically important genes for crop improvement.

Novel insights into host specificity of Pyricularia oryzae and Pyricularia grisea in the infection of gramineous plant roots.

Pyricularia oryzae and Pyricularia grisea are pathogens that cause blast disease in various monocots. It has been reported that P. oryzae infects the leaves and roots of rice via different mechanisms. However, it is unclear to what extent the tissue types affect the host specificities of P. oryzae and P. grisea. Here, we evaluated the tissue‐specific infection strategies of P. oryzae and P. grisea in various gramineous plants. Generally, mycelial plug inoculation caused root browning but the degree of browning did not simply follow the disease index on leaves. Interestingly, the Triticum and Digitaria pathotypes caused strong root growth inhibition in rice, wheat, and barley. Moreover, the Digitaria pathotype inhibited root branching only in rice. Culture filtrate reproduced these inhibitory effects on root, suggesting that some secreted molecules are responsible for the inhibitions. Observation of root sections revealed that most of the infection hyphae penetrated intercellular spaces and further extended into root cells, regardless of pathotype and host plant. The infection hyphae of Digitaria and Triticum pathotypes tended to localize in the outer layer of rice roots, but not in those of wheat and barley roots. The infection hyphae of the Oryza pathotype were distributed in both the intercellular and intracellular spaces of rice root cells. Pathogenesis‐related genes and reactive oxygen species accumulation were induced after root inoculation with all combinations. These results suggest that resistance reactions were induced in the roots of gramineous plants against the infection with Pyricularia isolates but failed to prevent fungal invasion.

Tolerance and Heavy Metal Accumulation Characteristics of Sasa argenteostriata (Regel) E.G. Camus under Zinc Single Stress and Combined Lead–Zinc Stress

Sasa argenteostriata (Regel) E.G. Camus is a gramineous plant with the potential for phytoremediation. In this study, we aimed to determine its tolerance to zinc stress and combined lead–zinc stress and the effect of zinc on its absorption and accumulation characteristics of lead. The results showed that S. argenteostriata had good tolerance to zinc stress, and S. argenteostriata was not significantly damaged when the zinc stress concentration was 600 mg/L. Under both zinc stress and combined lead–zinc stress, the root was the main organ that accumulated heavy metals in S. argenteostriata. The presence of zinc promoted the absorption of lead by the root of S. argenteostriata, and the lead content in the root under PZ1, PZ2, PZ3 and PZ4 treatments was 2.15, 4.31, 4.47 and 6.01 times that of PZ0 on the 20 days. In the combined lead–zinc stress treatments, the toxicity of heavy metals to S. argenteostriata was mainly caused by lead. Under high concentrations of combined lead–zinc stress (PZ4), the proportion of zinc in the leaf of S. argenteostriata on the 20 days increased, which was used as a tolerance strategy to alleviate the toxicity of lead.

Biodegradation of Gramineous Lignocellulose by Locusta migratoria manilensis (Orthoptera: Acridoidea)

Exploring an efficient and green pretreatment method is an important prerequisite for the development of biorefinery. It is well known that locusts can degrade gramineous lignocellulose efficiently. Locusts can be used as a potential resource for studying plant cell wall degradation, but there are few relative studies about locusts so far. Herein, some new discoveries were revealed about elucidating the process of biodegradation of gramineous lignocellulose in Locusta migratoria manilensis. The enzyme activity related to lignocellulose degradation and the content of cellulose, hemicellulose, and lignin in the different gut segments of locusts fed corn leaves were measured in this study. A series of characterization analyses were conducted on corn leaves and locust feces, which included field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction pattern (XRD), and thermogravimetric (TG) analysis. These results showed that the highest activities of carboxymethyl cellulase (CMCase), filter paper cellulase (FPA), and xylanase were obtained in the foregut of locusts, which strongly indicated that the foregut was the main lignocellulose degradation segment in locusts; furthermore, the majority of nutritional components were absorbed in the midgut of locusts. The activity of CMCase was significantly higher than that of xylanase, and manganese peroxidase (MnPase) activity was lowest, which might be due to the basic nutrition of locusts being cellulose and hemicellulose and not lignin based on the results of FE-SEM, FTIR, XRD, and TG analysis. Overall, these results provided a valuable insight into lignocellulosic degradation mechanisms for understanding gramineous plant cell wall deconstruction and recalcitrance in locusts, which could be useful in the development of new enzymatic pretreatment processes mimicking the locust digestive system for the biochemical conversion of lignocellulosic biomass to fuels and chemicals.

Total Barley Maiya Alkaloids Prevent Increased Prolactin Levels Caused by Antipsychotic Drugs and Reduce Dopamine Receptor D2 via Epigenetic Mechanisms.

Background: The dopamine D2 receptor (DRD2) plays an important role in the increased prolactin (PRL) levels associated with the pathogenesis of antipsychotic drugs (ADs). Elevated prolactin levels can affect people’s quality of life. Maiya alkaloids has been used to treat diseases associated with high PRL levels. Maiya, is a processed product of the mature fruits of Hordeum vulgare L. (a gramineous plant) after sprouting and drying and also a common Chinese herbal drug used in the clinic, is traditionally used to treat abnormal lactation, and is currently used clinically for the treatment of abnormal PRL levels. Aims: Epigenetic mechanisms can be related to DRD2 expression. We investigated the role of DRD2 methylation in the induction of PRL expression by ADs and the mechanism underlying the effects of total barley maiya alkaloids (TBMA) on this induction. Methods: The methylation rate of DRD2 in 46 people with schizophrenia who took risperidone was detected by MassARRAY sequencing. Humans were long term users of Ris. Seventy Sprague Dawley female rats were divided into seven groups. A rat model of risperidone-induced PRL was established, and the potential protective effects of TBMA and its components [e.g., hordenine (Hor)] on these increased PRL levels were investigated. The PRL concentration was detected by Enzyme-linked immunosorbent assay. PRL, DRD2, and DNA methyltransferase (DNMT1, DNMT3α, and DNMT3β) protein and mRNA expression were detected by western blotting and real-time polymerase chain reaction (RT-PCR), respectively. The positive rate of methylation in the DRD2 promoter region of rats was detected by MassARRAY sequencing. Results: Clinical studies showed that the positive rate of DRD2 methylation associated with increased PRL levels induced by ADs was significantly higher than in the normal prolactinemia (NPRL) group. In vivo and vitro, TBMA and Hor inhibited this induction of PRL expression and increased DRD2 expression by inhibiting the expression of the DNMTs. Conclusions: TBMA and hordenine increased DRD2 expression by inhibiting DNMT-dependent DRD2 methylation.

Characterization of Stem Nodes Associated with Carbon Partitioning in Maize in Response to Nitrogen Availability.

Stem node has been found to be a hub for controlling mineral nutrient distribution in gramineous plants. However, the characteristics of stem nodes associated with whole-plant carbon partitioning in maize (Zea mays L.) and their responses to nitrogen (N) availability remains elusive. Maize plants were grown in greenhouse under low to high N supply. Plant growth, sugar accumulation, and sugar transporters in nodes and leaves, as well as the anatomical structure of nodes, were investigated at vegetative phase. When compared to N-sufficient plants, low-N availability stunted growth and resulted in 49–64% less sugars in leaves, which was attributed to low photosynthesis or the accelerated carbon export, as evidenced by more 13C detected further below leaf tips. Invariably higher sugar concentrations were found in the stem nodes, rather than in the leaves across N treatments, indicating a crucial role of nodes in facilitating whole-plant carbon partitioning. More and smaller vascular bundles and phloem were observed in stem nodes of N-deficient plants, while higher sugar levels were found in the bottom nodes than in the upper ones. Low-N availability upregulated the gene expressions of sugar transporters, which putatively function in nodes such as ZmSWEETs and ZmSUTs at the bottom stem, but suppressed them in the upper ones, showing a developmental impact on node function. Further, greater activity of sugar transporters in the bottom nodes was associated with less sugars in leaves. Overall, these results highlighted that stem nodes may play an important role in facilitating long-distance sugar transport in maize.

Morpho-molecular characterisation of Arecophila, with A.australis and A.clypeata sp. nov. and A.miscanthi comb. nov.

Three arecophila-like fungal samples were collected on dead culms of gramineous plants in China. Morphological studies of our new collections and the herbarium specimen of Arecophilagulubiicola (generic type) were conducted and the morphological affinity of our new collections with Arecophila was confirmed. Maximum likelihood and Bayesian analyses using combined ITS, LSU, rpb2 and β-tubulin data from our collections revealed the phylogeny of Cainiaceae. The monospecific genus Alishanica (type species Al.miscanthi), which had been accepted in Cainiaceae, is revisited and synonymised under Arecophila. Based on morphology and phylogeny, Arecophilaaustralis sp. nov. and A.clypeata sp. nov. are introduced as new species, while A.miscanthi is a new record for China. All the new collections are illustrated and described.

Effects of Host Plant and Insect Generation on Shaping of the Gut Microbiota in the Rice Leaffolder, Cnaphalocrocis medinalis.

Gut microbes in insects may play an important role in the digestion, immunity and protection, detoxification of toxins, development, and reproduction. The rice leaffolder Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae) is a notorious insect pest that can damage rice, maize, and other gramineous plants. To determine the effects of host plants and generations on the gut microbiota of C. medinalis, we deciphered the bacterial configuration of this insect pest fed rice or maize for three generations by Illumina MiSeq technology. A total of 16 bacterial phyla, 34 classes, 50 orders, 101 families, 158 genera, and 44 species were identified in C. medinalis fed rice or maize for three generations. Host plants, insect generation, and their interaction did not influence the alpha diversity indices of the gut microbiota of C. medinalis. The dominant bacterial taxa were Proteobacteria and Firmicutes at the phylum level and Enterococcus and unclassified Enterobacteriaceae at the genus level. A number of twenty genera coexisted in the guts of C. medinalis fed rice or maize for three generations, and their relative abundances occupied more than 90% of the gut microbiota of C. medinalis. A number of two genera were stably found in the gut of rice-feeding C. medinalis but unstably found in the gut microbiota of maize-feeding C. medinalis, and seven genera were stably found in the gut of maize-feeding C. medinalis but unstably found in the gut of rice-feeding C. medinalis. In addition, many kinds of microbes were found in some but not all samples of the gut of C. medinalis fed on a particular host plant. PerMANOVA indicated that the gut bacteria of C. medinalis could be significantly affected by the host plant and host plant × generation. We identified 47 taxa as the biomarkers for the gut microbiota of C. medinalis fed different host plants by LEfSe. Functional prediction suggested that the most dominant role of the gut microbiota in C. medinalis is metabolism, followed by environmental information processing, cellular processes, and genetic information processing. Our findings will enrich the understanding of gut bacteria in C. medinalis and reveal the differences in gut microbiota in C. medinalis fed on different host plants for three generations.

High-quality chromosome-scale de novo assembly of the Paspalum notatum \u2018Flugge\u2019 genome

BackgroundPaspalum notatum ‘Flugge’ is a diploid with 20 chromosomes (2n = 20) multi-purpose subtropical herb native to South America and has a high ecological significance. It is currently widely planted in tropical and subtropical regions. Despite the gene pool of P. notatum ‘Flugge’ being unearthed to a large extent in the past decade, no details about the genomic information of relevant species in Paspalum have been reported. In this study, the complete genome information of P. notatum was established and annotated through sequencing and de novo assembly of its genome.ResultsThe latest PacBio third-generation HiFi assembly and sequencing revealed that the genome size of P. notatum ‘Flugge’ is 541 M. The assembly result is the higher index among the genomes of the gramineous family published so far, with a contig N50 = 52Mbp, scaffold N50 = 49Mbp, and BUSCOs = 98.1%, accounting for 98.5% of the estimated genome. Genome annotation revealed 36,511 high-confidence gene models, thus providing an important resource for future molecular breeding and evolutionary research. A comparison of the genome annotation results of P. notatum ‘Flugge’ with other closely related species revealed that it had a close relationship with Zea mays but not close compared to Brachypodium distachyon, Setaria viridis, Oryza sativa, Puccinellia tenuiflora, Echinochloa crusgalli. An analysis of the expansion and contraction of gene families suggested that P. notatum ‘Flugge’ contains gene families associated with environmental resistance, increased reproductive ability, and molecular evolution, which explained its excellent agronomic traits.ConclusionThis study is the first to report the high-quality chromosome-scale-based genome of P. notatum ‘Flugge’ assembled using the latest PacBio third-generation HiFi sequencing reads. The study provides an excellent genetic resource bank for gramineous crops and invaluable perspectives regarding the evolution of gramineous plants.

Fullerenol affects maize plants depending on their iron status

Although fullerene (C60) has attracted great interest as a carbon-based nanomaterial with unique properties, today, little is known about the interaction of its water-soluble derivates, including fullerenol with higher plants. Here, we investigated how fullerenol [C60(OH)22-24] affects Zea mays, as a Strategy II plant, depending on its iron status. Iron deficiency chlorosis is a common nutritional disorder affecting plants. Maize plants were grown hydroponically, either with [+FeII (ferrous) or +FeIII (ferric)] or in Fe-free (-FeII and -FeIII) nutrient solution and with or without a fullerenol supply. Fullerenol affected plants differently depending on their Fe status. The beneficial effects of fullerenol were observed in the FeII-deprived plants, including successful suppression of plant Fe-deficiency chlorosis mainly in the younger (basal and middle) region of the leaf blade. This region expressed more severe chlorosis as compared with the older (apical) region of the leaf blade. These changes were accompanied by a significant increase in leaf active Fe and lowering the root apoplastic Fe, suggesting that fullerenol may enhance Fe mobilization in the roots, helping to alleviate Fe deficiency chlorosis. By contrast, there were no observable effects in the FeIII-deprived plants being significantly lower in the root apoplastic Fe as compared with the FeII-deficient plants. Additionally, fullerenol did not affect the Fe-sufficient plants, irrespective of the Fe species (FeIII-EDTA or FeII-EDTA) used as Fe-sources. Our results provide new evidence for the beneficial role of Fe-fullerenol interactions in the enhancement of gramineous plant tolerance to Fe deficiency conditions, which are one of the major limiting factors for crop production all over the world.

Alpine constructed wetlands: A metagenomic analysis reveals microbial complementary structure

Constructed wetlands (CWs) are used to water treatment worldwide, however their application at high-altitude is poorly studied. In order to survive mountain winters, CWs rely on native flora and associated microbial communities. However, the choice of plant-microbes pairs more suitable for water treatment is challenging in alpine environments. Using a metagenomic approach, we investigated the composition of prokaryotes and fungal communities, through extensive sampling inside a constructed wetland in the SW-Alps. Best performing plant species were searched among those hosting the most diverse and resilient microbial communities and to this goal, we analysed them in the natural environment also. Our results showed that microbial communities were less diverse in the CW than at natural conditions, and they differed from plant to plant, revealing a clear variation in taxonomic composition between forbs and gramineous plants. Carex rostrata, Deschampsia caespitosa and Rumex alpinus hosted bacteria very active in N-cycles. Moreover, fungal and prokaryotic communities associated to R. alpinus (Polygonaceae) turned to be the richest and stable among the studied species. In our opinion, this species should be prioritized in CWs at high elevations, also in consideration of its low maintenance requirements.

Gut microbiome of the largest living rodent harbors unprecedented enzymatic systems to degrade plant polysaccharides

The largest living rodent, capybara, can efficiently depolymerize and utilize lignocellulosic biomass through microbial symbiotic mechanisms yet elusive. Herein, we elucidate the microbial community composition, enzymatic systems and metabolic pathways involved in the conversion of dietary fibers into short-chain fatty acids, a main energy source for the host. In this microbiota, the unconventional enzymatic machinery from Fibrobacteres seems to drive cellulose degradation, whereas a diverse set of carbohydrate-active enzymes from Bacteroidetes, organized in polysaccharide utilization loci, are accounted to tackle complex hemicelluloses typically found in gramineous and aquatic plants. Exploring the genetic potential of this community, we discover a glycoside hydrolase family of β-galactosidases (named as GH173), and a carbohydrate-binding module family (named as CBM89) involved in xylan binding that establishes an unprecedented three-dimensional fold among associated modules to carbohydrate-active enzymes. Together, these results demonstrate how the capybara gut microbiota orchestrates the depolymerization and utilization of plant fibers, representing an untapped reservoir of enzymatic mechanisms to overcome the lignocellulose recalcitrance, a central challenge toward a sustainable and bio-based economy.

内蒙古草原布氏田鼠与绵羊的营养生态位研究

PDF HTML阅读 XML下载 导出引用 引用提醒 内蒙古草原布氏田鼠与绵羊的营养生态位研究 DOI: 10.5846/stxb202109142578 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31971429，31272320） Trophic niches of Brandt's vole (Lasiopodomys brandtii) and sheep (Ovis aries) in the Inner Mongolia Grassland Author: Affiliation: Fund Project: The National Natural Science Foundation of China (31971429; 31272320) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:放牧活动对小型啮齿动物种群数量的影响是草原生态系统研究中的热点问题，确定绵羊和小型啮齿动物的营养生态位关系对于草原生态系统的管理具有重要的作用。运用粪便显微分析法分析了内蒙古草原动物生态研究站大型野外围栏内布氏田鼠和绵羊在6-9月份的食谱组成，确定两种草食动物食性选择和营养生态位的变化，从食物利用途径揭示放牧活动对布氏田鼠种群数量的影响方式及二者之间的竞争与共存关系。研究结果表明：围栏中共有23种植物，其中糙隐子草、克氏针茅、羊草和刺藜是围栏中的优势植物；布氏田鼠共取食10种植物，绵羊共取食8种植物，禾本植物为两种动物的主要采食植物。布氏田鼠和绵羊的喜食植物种类都存在季节性变化；除7月外，两种动物的食物多样性与围栏植物多样性有显著的正相关关系，表明动物的食性选择受植物资源变化的影响。布氏田鼠和绵羊具有很高的营养生态位重叠度，除8月（0.691）外，6、7、9月份的营养生态位重叠度均高于0.9，表明二者之间存在激烈的食物竞争；放牧活动极显著地降低了禾本科植物的地上生物量，导致布氏田鼠的食物数量减少；放牧处理下布氏田鼠的喜食植物的物种数和营养生态位宽度（除9月）增加，导致布氏田鼠的食物质量下降。以上研究结果说明，较高的营养生态位重叠度引起动物间激烈的食物竞争；放牧会影响围栏中植物资源的变化，进而影响布氏田鼠的食性选择，放牧活动可能通过降低布氏田鼠的食物数量和质量对其种群数量产生负面效应；这也说明适度的放牧活动在增加人类对草场利用的同时，又可降低小型啮齿动物的数量及危害。 Abstract:The influence of grazing activities on the population of small rodents is a hot issue in grassland ecosystem research. The determination of trophic niche relationship between sheep and small rodents plays an important role on the management of grassland ecosystems. In present study, microscopic analysis of feces was applied to analyze the diet composition of Brandt's voles and sheep, whose fecal samples were collected from the Animal Ecology Research Station located in the Maodeng pasture (Xilinhot, Inner Mongolia, China) from June to September, 2012. The changes in diet selection and trophic niches of the two herbivores would be determined to reveal the patterns by which the population of Brandt's vole was affected by grazing activities, and the relationship of competition and coexistence between these two herbivores from the perspective of food utilization. Our results showed that a total of 23 plant species were found in the fence, with Cleistogenes squarrosa, Stipa krylovii, Leymus chinensis, and Dysphania aristata being the dominant plants. Brandt's vole and sheep fed on 10 and 8 plant species, respectively. Gramineous plants were the main forage plants for both animals. Brandt's vole and sheep had their favorite plant species which varied in different seasons; except for that in July, there was a significantly positive correlation between dietary diversity of animals and plant diversity within the fences, suggesting an effect of changes in available plant resources on animals' diet selections. The trophic niche overlap between Brandt's vole and sheep was higher than 0.9 except for that in August (0.691), indicating that there was fierce food competition between the two. In addition, the grazing activities significantly reduced the aboveground biomass of plants from the Gramineae family, leading to a decrease in the quantity of food for Brandt's vole; and grazing activities significantly increased the number of plant species favored by Brandt's voles and the breadth of its trophic niche (except for September), leading to a decrease in the quality of food for Brandt's vole. These results indicated that high trophic niche overlap could cause fierce food competition between animals; grazing could affect the diet selection of Brandt's voles by influencing changes of plant resources in the fences, and grazing activities may have a negative effect on the population of Brandt's vole through reducing the quality and quantity of its food. These findings suggest that moderate grazing activities not only increase the utilization of pastures but also reduce the population of small rodents and their damage. 参考文献 相似文献 引证文献

A New Detection of the Invasive Mexican Rice Borer (Lepidoptera: Crambidae) From Georgia in the United States Based on Morphological and Molecular Data

Abstract The Mexican rice borer, Eoreuma loftini (Dyar), is an invasive herbivore that attacks many gramineous host plants. The species is an economic pest of several grass crops in North America including sugarcane (Saccharum spp.), rice (Oryza sativa), corn (Zea mays), and sorghum (Sorghum bicolor). The species was first detected in the United States in 1980 and has since expanded its range eastward along the Gulf Coast reaching Louisiana in 2008. A disjointed introduction was detected in Florida in 2012, though range expansion of this population within the state has been limited. Most recently, a separate introduction was detected along the Atlantic coast of Georgia near the South Carolina border (32.19884° N, 81.35894° W). Larvae were collected from sugarcane in 2020 and 2021 and identified as E. loftini. The identification was confirmed with genetic analysis showing >99% similarity with most mitochondrial cytochrome c oxidase subunit 1 (COI) sequences of known E. loftini. This is the furthest north and east of any established population in North America. Potential routes of introduction and impacts to crop production along the U.S. Atlantic Coast are discussed.

Evaluating the effects of different silage additives on silage quality and in vitro digestion values of the silages of leguminous and gramineous forage plants grown without fertilizer and irrigation in central Anatolian arid conditions

Evaluating the effects of different silage additives on silage quality and in vitro digestion values of the silages of leguminous and gramineous forage plants grown without fertilizer and irrigation in central Anatolian arid conditions

Diversity and function of microbial communities in the sand sheath of Agropyron cristatum by metagenomic analysis

The roots of most gramineous plants are surrounded by a variety of microorganisms; however, few studies have focused on the rhizosheath of psammophytes. Therefore, in this study, we used Illumina HiSeq high-throughput sequencing technology to analyse the composition and functional diversity of microbial communities in the rhizosheath of sand-grown Agropyron cristatum (L.) Gaertn. We found that the number of species and functions of microbial communities gradually decreased from the rhizosheath to the bulk soil. Thus, the microbial composition of the rhizosheath was richer and more diverse, and the abundance of bacteria, including Sphingosinicella, Rhizorhabdus, Friedmanniella, Geodermatophilus, Blastococcus, and Oscillatoria, was higher, and the abundance of fungi, such as Mycothermus, was higher. The abundance of CO2 fixation-related genes (acsA, Pcc, and cbbL) in the carbon cycle; NO3–, NO2–, NH2OH, and N2 transformation genes (nrtP, nirS, hao, and nifK) in the nitrogen cycle; soxB/A/C, Sat, and dsrB genes in the sulphur cycle; and 1-phosphate mannitol dehydrogenase (MtlD) gene and polyketide synthase gene (pks) were higher in the rhizosheath than in the bulk soil, as well as genes related to phosphorus uptake in the phosphorus cycle. Our findings showed that the rhizosheath may host the predominant microbial species related to the formation of a rhizosheath.

Changes in "natural antibiotic" metabolite composition during tetraploid wheat domestication

Gramineous plants protect their seeds from a variety of biotic stresses by producing toxic and deterrent secondary metabolites such as benzoxazinoids. It is unclear how the composition and abundance of these natural toxins has changed over the course of crop-plant domestication. To address this uncertainty, we characterized differences in metabolic levels of benzoxazinoids and their derivatives, between four lines of tetraploid wheat: wild emmer wheat (WEW), the direct progenitor of modern wheat; non-fragile domesticated emmer wheat (DEW), which was first domesticated about 11,000 years ago; the subsequently developed non-fragile and free-threshing durum landraces (LD); and modern durum (MD) varieties. Three-dimensional principal component analysis of mass spectrometry data of wheat metabolites showed with high resolution clear differences between metabolic profiles of WEW, DEW, and durum (LD + MD) and similarity in the metabolic profiles of the two durum lines (LD and MD) that is coherent with the phylogenetic relationship between the corresponding wheat lines. Moreover, our results indicated that some secondary metabolites involved in plant defense mechanisms became significantly more abundant during wheat domestication, while other defensive metabolites decreased or were lost. These metabolic changes reflect the beneficial or detrimental roles the corresponding metabolites might play during the domestication of three taxonomic subspecies of tetraploid wheat (Triticum turgidum).

Efficiency of Three Egg Parasitoid Species on Fall Armyworm (Lepidoptera: Noctuidae) in Laboratory and Field Cages

Abstract Egg parasitoids are the most used natural enemies in biological control of Spodoptera frugiperda (J.E. Smith), a pest of gramineous plants native to the Americas that recently invaded Africa and some countries of Asia. Although Trichogramma pretiosum (Riley) is one of the main species used against this pest, there are other species with equal or greater parasitism potential. The objective of this work was to compare, in laboratory and in field cages, the parasitism of Telenomus remus Nixon, Trichogramma atopovirilia (Oatman and Platner), and T. pretiosum on S. frugiperda eggs. Telenomus remus and T. atopovirilia reached the highest percentages of parasitism in laboratory (>70%) which did not differ statistically from each other. Trichogramma pretiosum had the lowest percentage of parasitism (29%) of the three. In the field cage assays, Te. remus parasitized 30% of the S. frugiperda egg masses, and T. pretiosum parasitized about 7.5% of the egg masses. These results underscore the importance of adequate selection of egg parasitoids for their use in biological control programs by augmentation against S. frugiperda.

Correlation of Genomic Compartments with Contrastive Modes of Functional Losses of Host Specificity Determinants During Pathotype Differentiation in Pyricularia oryzae.

The specificity between pathotypes of Pyricularia oryzae and genera of gramineous plants is governed by gene-for-gene interactions. Here, we show that avirulence genes involved in this host specificity have undergone different modes of functional losses dependent on or affected by genomic compartments harboring them. The avirulence of an Eleusine pathotype on wheat is controlled by five genes, including PWT3, which played a key role in the evolution of the Triticum pathotype (the wheat blast fungus). We cloned another gene using an association of its presence or absence with pathotypes and designated it as PWT6. PWT6 was widely distributed in a lineage composed of Eleusine and Eragrostis isolates but was completely absent in a lineage composed of Lolium and Triticum isolates. On the other hand, PWT3 homologs were present in all isolates, and their loss of function in Triticum isolates was caused by insertions of transposable elements or nucleotide substitutions. Analyses of whole-genome sequences of representative isolates revealed that these two genes were located in different genomic compartments; PWT6 was located in a repeat-rich region, while PWT3 was located in a repeat-poor region. These results suggest that the course of differentiation of the pathotypes in P. oryzae appears to be illustrated as processes of functional losses of avirulence genes but that modes of the losses are affected by genomic compartments in which they reside.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.